*{
  margin: 0;
  padding: 0;
}
#div1{
  width: 100px;
  height: 100px;
  background: green;
  position: absolute;
  left: 0;
  top: 0;
}
#p1{
  width: 94px;
  height: 94px;
  position: absolute;
  left: 0;
  top: 0;
  border: 3px dashed red;
}
